Process for aggregating difficult to aggregate particles and the product thereof



July 26, 1966 A. M. SWANSON ETAL 3,262,788

PROCESS FOR AGGREGATING DIFFICULT TO AGGREGATE PARTICLES AND THE PRODUCT THEREOF Filed June 25, 1963 2 Sheets-Sheet 1 Difficult to Aggregate Easily Aggregated Particulate Material l Aggregating Agent 2 Dry Mixing 3 i Wetting 4 i Drying 5 i Finished Aggregated Product 6 2? 28 I |s l I 30 am 2t 23 fiz E INVENTOR.

ARTHUR M. SWANSON 8i DOUGLAS J. FENSKE,

ATTORNEY July 26, 1966 A. M. SWANSON ETAL Filed June 25, 1963 2 Sheets-Sheet. 2

RATE OF WATER SORPTION OF VARIOUS SUGARS of sugar after sorbing water Anhydrous lactose Anhydrous glucose Lactose monohydrate 9 Reconstitution time after aggregation 9, Reconstitution time before aggregation Egg albumen W Attained weight W, Original weight of dry sugar TIME F195 IO I.O X D D C 8 .B 5 Egg y 3 Wheat flour 3 5 Whole egg 3: 99 O 4 albumen A 2 g 2 .2 B]

IO 20 3O 4O O 0 "/0 Anhydrous lactose IO 4O Anhydrous lactose INVENTOR. ARTHUR M. SWANSON 8: DOUGLAS J. FENSKE XW 720w ATTORNEY United States Patent s eaves AGGREGATING nrrrrcurr ".ro AND "run rRoDUer The present application is a continuation-in-part of our copending application Serial No. 190,637, filed April 27, 1962, now abandoned.

This invention relates generally to the aggregation of finely divided particles, and more particularly to the aggregation of particles of material which have been difficult, if not impossible, to aggregate, and the product formed by such an aggregation process.

Most dried materials commercially available today are in the form of relatively small, particulate particles. This is true of spray-dried, roller dried, tray dried or belt dried in atmosphere or vacuum, and crystallized materials. The spray-dried materials are in the form of small, particulate particles when they are removed from the dryer, Whereas the products resulting from. roller, tray or belt drying and crystallizing processes are pul verized after being removed from the dryers and the crystallizer in order to give a fairly uniform particle size and appearance to the product. The resulting particle size of all of the above mentioned products is approximately the same, and is so exceedingly small that the particles will tend to ball up or form incompletely wetted lumps when they are added to a suitable liquid. Use of such product therefore requires a great deal of time and eifort to effect satisfactory reconstitution in water or other liquids. Such poor wetting and reconstituting characteristics have handicapped the popular acceptance of these finely divided dried materials.

It is well known that when certain finely divided dried particles are aggregated, the wettability and dispersibility of such materials in liquids is greatly increased. An example of such an aggregated product is the product commonly known as instant nonfat dried milk.

Aggregation is a process whereby small particulate particles are caused to adhere to each other in random fashion, resulting in porous, open structured aggregates of greater size than the original individual particles. The porous, open structure and increased particle size are the characteristics which are responsible for the increased flowability, wettability, and dispersibility of the aggregated product in liquids.

In the conventional process of aggregation, the particulate particles are subjected to a stream of warm, moist air, causing moisture to be sorbed onto the surface of the particles to produce surface tackiness. The air stream is of suthcient velocity to cause random collisions between the particles. The surface tackiness causes such colliding particles to be bonded together, and the bonds thus formed during the wetting of the particles are retained when the added moisture is removed by a stream of warm, dry air.

Such conventional aggregation processes have been limited to the aggregation of dried particles which will readily sorb moisture when wetted by the moist, warm air, which will stick together upon colliding after wetting, and which will remain stuck or bonded together after being dried by the warm, dry air. Dried particles which do not possess all three of these characteristics have been difficult, if not impossible, to aggregate by prior known methods. Thus such powders fail to achieve the same degree of improved fiowability, wettability, and dispersibility that spray-dried non-fat dry milk does when 3,252,738 Patented Juiy 26, i956 subjected to the same aggregating process. By Way of example only, the following products are among those which are difiicult, if not impossible, to aggregate by prior known processess: dried egg products, including egg albumen, whole egg, fortified egg and egg yolk; cocoa; dried meats and meat products; dried food mixes, such as pancake mix, soup mixes and various bakery mixes; flours, numerous chemicals and biological materials, including dried glues, fertilizers, enzymes, pesticides, herbicides, and other finely divided powder substances; and numerous dried pharmaceutical products.

By employing the methods set forth in this application, the above named dried materials and any other such materials which cannot be aggregated by conventional means can be converted into products which have the required particle size and porous nature to give materially increased flowability, wettability and dispersibility. These products, when aggregated according to the teachings set forth in this invention, will reconstitute into usable form with a minimum of time, effort and equipment.

Accordingly, it is a primary object of our invention to provide a relatively inexpensive process for aggregating previously difiicult to aggregate finely divided dry materials.

It is a further object of our invention to provide a process for aggregating previously difiicult to aggregate finely divided dry particles whereby to substantially eliminate tendencies of such particles to cake and render them free-flowing.

It is another object of our invention to provide a process for aggregating previously difiicult to aggregate finely divided particles which may be carried out with existing conventional aggregating equipment.

It is another object of our invention to provide a controlled process for aggregating previously diificult to aggregate finely divided particles which allows a minimum of crystallization of the aggregated product.

It is a still further object of our invention to provide a process for aggregating previously difficult to aggregate finely divided materials which does not unduly increase the per unit cost of such materials.

It is another object of our invention to provide a stable aggregated product having as its principal ingredient a previously difiicult to aggregate material.

Other objects and advantages of the present invention will be readily apparent from the following detailed description taken in conjunction with the accompanying drawings.

In the drawings:

FIG. 1 is a flow diagram indicating a general procedure for carrying out our process.

FIG. 2 is a schematic diagram illustrating one type of conventional apparatus by which our process may be practiced.

FIG. 3 is a graph illustrating the rate of water sorption of various sugars.

FIG. 4 is a graph illustrating the aggregation charactertistics of various dried particulate materials aggregated by our process.

FIG. 5 is a graph illustrating the elfect of reconstitutability of aggregating various particles by our process.

In general, the present process involves the addition of an easily aggregated aggregating agent to the difficult to aggregate product material to provide, when subjected to a warm, moist atmosphere, a tacky nucleus onto which the nontacky product particles to be aggregated are randomly adhered. Referring to FIG. 1, which illustrates the various steps involved in performing our process, the difficult to aggregate particulate material 1 and the easly aggregated agent 2 are dry mixed and blended in the proper proportions 3. The dry blended mixture may include between approximately and 50% aggregating agent as will be more fully described as the description progresses. The dry mixture is then injected into a stream of warm, moist air to elfect wetting 4 of the particles to cause the aforementioned aggregation. The aggregated particles are then subjected to quick drying 5 to produce the desired dry aggregated product 6. The majority of the aggregates in such product consist of difficult to aggregate particles firmly adhered to particles of aggregating agent in random fashion. However, a small percentage of such aggregates may be formed of aggregating agent only or of difficult to aggregate particles only.

The dry materials which are treated by the method set forth in this invention exhibit properties which are uniquely different from those not so treated or processed. The properties produced in the aggregated product of our process are those of increased particle sie, improved flowability, wettabil-ity, dispersibility and reconstitutability in liquid, and prevention of caking.

In order for a powder to be aggregated, it must exhibit certain properties as previously mentioned. The first, and perhaps the most important property is that of hydroscopicity, that is, the property of readily sorbing and retaining moisture. The sorption of water is necessary to obtain a state of surface tackiness which will allow the powder particles to be randomly adhered to each other. However, all hydroscopic particles do not become sticky when they absorb moisture, and those which do not develop such stickiness are not easily aggregated. A third property which must be present is that of retention of the aggregated form when the aggregates are subsequently re- -dried and packaged. This term may be defined as aggregate strength.

For the purposes of this application, the term difficult .to aggregate particles refers to those particles which are substantially lacking one or more of the above named properties necessary for aggregation. The term aggregating agent may include all those materials which possess all three of the above named properties. The selection of the particular aggregating agent to be used will depend on the degree to which the particular available aggregating agents possess the above properties, the comparative cost of the available agents, the various additional properties such as taste, composition, and so forth of the available agents, and the particular product which is desired to be aggregated. Examples of suitable aggregating agents are: amorphous lactose, amorphous whey, and modified amorphous whey. Such aggregating agents may be used singly, or in combination, or with suitable extenders.

As previously indicated in this description, we have found that cocoa may be satisfactorily aggregated by our process. Peebles et al. US. Pat. No. 2,850,388 and Carlson et al. U.S. Pat. No. 3,013,881 taught that mixtures containing relatively small amounts of cocoa may be aggregated to form an instant powdered chocolate drink product. However, the present process provides for the treatment of lecithinated or non-lecithinated cocoa powder to form an aggregated product, the major portion of which is cocoa. Such a process eliminates the need for adding large amounts of nonfat dry milk, or other substances to achieve the aggregation. The aggregated cocoa product produced by our process has a variety of uses in the food industry, and is not limited to use as a chocolate drink product.

Among the above mentioned aggregating agents, the one which is perhaps most often useful is anhydrous lactose. Anhydrous lactose may be obtained by spray drying dissolved lactose, and exists in the amorphous or glass state. It exhibits all the above mentioned properties of hydroscopicity, surface tackiness and aggregate strength. Anhydrous lactose exhibits a very unique property in that while it is very hydrosoopic, it is also quite insoluble as compared to other common sugars. Such relatively low solubility makes the anhydrous lactose relatively easy to handle in most conventional aggregators and minimizes plastering within the aggregator. When particles of anhydrous lactose are injected into a stream of humid air, water is immediately sorbed onto the surface of the lactose particles, due to their high hydroscop'icity. The water will cause the surfaces of the lactose particles to become sticky, and these sticky surfaces will cause colliding difiicult to aggregate powder particles to adhere to the lactose particles and form aggregates. The bonds which are formed between the anhydrous lactose particles and the powder particles are strong enough to resist fracture during subsequent redrying and packaging operations.

The moisture sorption property of anhydrous lactose is due to its strong desire to assume a stable configuration. The most stable form of lactose is that of the monohydrate or crystalline form. The following reaction will show the hydrating process.

There is a strong tendency for the above reaction to go to the right. In order for the reaction to progress, some water must be present to combine with the anhydrous lactose as shown on the left side of the equation. It is this strong tendency of the anhydrous lactose to assume the stable monohydrate form that causes the anhydrous lactose to quickly sorb water. Once the monohydrate is formed, there is no longer any driving force which will cause the lactose to sorb more water. The strong tendency of anhydrous lactose to sorb water is illustrated graphically in FIG. 3, wherein the vertical axis represents the ratio of the attained weight of the various sugars shown after sorbing water, to the original weight of the sugars in the dry state. The horizontal axis represents increasing time. It is obvious from FIG. 3 that in a given period of time anhydrous lactose will sorb a much greater amount of water than will lactose monohydrate, which sorbs very little water.

It is, of course, obvious from examination of the above reaction, that the longer the given quantity of anhydrous lactose is allowed to remain wetted, the more complete will be the conversion of the lactose to the monohydrate or crystalline form. In aggregators of the type shown in Peebles US. Patents Nos. 2,856,318 and 2,850,388, the aggregated product is typically allowed to remain in the wetted condition for a period of from one to several minutes so as to achieve a high degree of crystallization of the bonds between the aggregated particles. However, we have found that such an extended wetting period of time is undesirable in the aggregation of most difficult to aggregate materials. We have found that when the dry mixed particles are wetted for a maximum period of about from two to eight seconds, very little, if any, crystallization of the anhydrous lactose will occur. When the wetted particles are quickly dried, the lactose will be dried in a substantially amorphous or glass state, and the bonds between the amorphous lactose and the diflicult to aggregate particles thus formed are sufiiciently strong to resist fracture during packaging and storage. The bonds thus formed are completely different than the crystalline bonds present in the products of the afore-mentioned Peebles patent. Such controlled wetting and quick drying eliminates the necessity for any resting or holding period while the aggregates are in the wetted condition, and substantially prevents any undesirable side reactions which often occur when the particles are allowed to remain wetted for a relatively substantial length of time. Common undesirable side effects which are produced by such extended wetting are flavor change, reduced storage life, and browning of the finished product. The presence of one or more of such side effects will, of course, depend upon the material which is being aggregated. Where such side effects are not objectionable or are unlikely to occur, such quick drying may not be necessary. With some difiicult to aggregate products such as, for example, certain pharmaceuticals and chemicals, no reduction of the moisture content of the aggregated product is necessary, and the redrying step may be eliminated completely. It is also pointed out that the aforementioned Peebles patents are limited to the processes for aggregating crystalline lactose powder and a particular spray dried chocolate product, which includes but a small percentage of pure cocoa mixed with nonfat dry milk and numerous other ingredients.

FIG. 4 shows the effect of the addition of various amounts of anhydrous lactose to several diflicult to aggregate materials. The vertical axis of the graph in FIG. 4 represents effective aggregation wherein zero represents no appreciable aggregation and represents maximum effective aggregation. The horizontal axis represents the percentage of anhydrous lactose in the aggregated dry mixture. It is seen that for a mixture of anhydrous lactose and wheat flour, maximum effective aggregation will occur when the mixture contains approximately 10% anhydrous lactose and 90% wheat flour. A mixture containing approximately 20% anhydrous lactose will produce maximum effective aggregation when either dried whole egg or dried egg albumen are to be aggregated. Dried egg yolk is most easily aggregated in a mixture containing between 10% and 20% anhydrous lactose. The exact percentage of anhydrous lactose which should be present in a given mixture will vary with the particular aggregatin apparatus which is used, its method of operation, and the amount of moisture which is applied. It can be seen from FIG. 4 that various dry mixtures of between about 5% and 50% anhydrous lactose will produce relatively good aggregation. For mixtures containing less than about 5% anhydrous lactose, the number of sticky anhydrous lactose particles in the wetted mixture is insufficient to cause aggregation of all the difiicult to aggregate particles present therein. For mixtures containing more than about 50% anhydrous lactose, the wetted mixture becomes too sticky to be prope ly handled in most aggregators. In such mixtures the aggregates which are formed become unduly large, making drying diflicult and causing the aggregating apparatus to become clogged. In most instances it is desirable to use only that amount of anhydrous lactose which is necessary to achieve the desired degree of aggregation. Addition of such minimal amounts of lactose produces a product which is only slightly sweeter than the initial diflicult to aggregate product, since lactose is one of the least sweet sugars. In addition, when minimum amounts of lactose are added, the per unit cost of the difiicult to aggregate material is only slightly increased.

FIG. 5 shows the effect which the addition of lactose has on the reconstitution time of the product. The vertical axis represents the ratio of reconstitution time after aggregation to reconstitution time before aggregation. When the ratio is equal to one, no improvement in reconstitution time over the original difiicult to aggregate finely divided materials is present. Decreasing values on the vertical axis illustrate improved reconstitution characteristics of the aggregated product. It can be seen from the figure that the reconstitution time decreases sharply as small amounts of anhydrous lactose are added to the difficult to aggregate products and aggregation begins to occur. It can be seen that an aggregated mixture of 80% dried egg albumen and 20% anhydrous lactose will reconstitute in about one-fifth the time necessary to reconstitute unaggregated egg albumen powder. An aggregated mixture of about 20% anhydrous lactose and 80% dried whole egg or dried egg yolk will reconstitute in less than one-tenth the time necessary to reconstitute unaggregated dried whole egg or dried egg yolk. A mixture of about 10% anhydrous lactose and 90% wheat flour has a reconstitution time of about that of unaggregated wheat flour. As the percentages of anhydrous lactose present in the dry mixture increases above the above mentioned values, the reconstitution time remains substantially the same.

Anhydrous whey is another good aggregating agent which is useful in some applications. Anhydrous whey contains a large proportion of amorphous lactose, and is considerably less expensive. However, the use of anhydrous whey as an aggregating agent is limited due to the presence therein of a salty taste and various whey proteins. Where such salty taste is not objectionable, as for example in various calf feeds, fertilizers, chemicals, and pharmaceuticals, the use of anhydrous whey may often be preferable because of its low cost. Also, proper treatment of anhydrous whey may be employed to produce a modified anhydrous whey in which these limiting characteristics are eliminated.

One possible form of conventional aggregating apparatus which is suitable for carrying out our novel process is shown in FIG. 2 of the drawings. The desired dry mix of difficult to aggregate powder and aggregating agent is placed in the supply hopper 12 and fed into the wetting tube or chamber 14 by means of feed screw 13 operated by motor 13a. The dry blend is exposed to an atmosphere of moist steam entering at pipe 15. The blended product and the wet stream are kept in constant motion through the wetting tube 1 by means of high velocity fan 16 operated by motor 17, which blows the product tangentially into wet cyclone 18. Fan 16 has air return 19.

" During the passage of the product through the wetting tube 14, the surfaces of the particles of aggregating agent become wet and sticky. As the sticky particles collide with the dilficult to aggregate particles in the wetting tube, the difficult to aggregate particles adhere to the sticky aggregating agent particles to form aggregates which are substantially larger than the individual particles of which the aggregates are comprised. The total moisture con-' tent of the mixture is preferably increased by between 2% and 6% in the wetting tube or chamber 14. The temperature in the wetting tube or chamber 14 may be between about F. and F. the optimum temperatures depending upon the air velocity and the composition of the product being treated. Of course, as different apparatus is used to carry out our process, the above values for moisture and temperature will vary somewhat to provide maximum effective aggregation.

After being forced from wetting tube 14, the aggregates pass through wet cyclone 18, and then drop from cyclone 18 into the redrying section 20. In redrying section 20 the aggregates are subjected to high velocity warm air from fan 21 operated by motor 21a and having filters 22 and heating coil 23 which heats the air. The aggregates are subjected to drying air at temperatures preferably ranging between about 200 F. and 500 F. The aggregates then begin to dry immediately as the product moves through the redrying section 20. The product is forced into tube 24 where it is subjected to forced air from fan 25 operated by motor 26. The product is separated from the driving air stream as it is forced from tube 24 through star valve 27. The product is substantially dry when it is deposited on the shaker table 28, though final drying to the desired moisture content is accomplished before it reaches the end of shaker table 28. The aggregated particles are sized by means of sizing rolls 29 and then placed in drum 30 through tube 31 for final pack-aging. The floor line between upper and lower levels of the plant is indicated by F in FIG. 2.

The lapse of time from the entry of the product into wetting tube or chamber 14 until it leaves tube 24 through star valve 27, ranges from about 5 to 20 seconds. The period of time between the initial wetting of the particles in Wetting tube 14 to drying of the particles in drying section 20 may be between about 2 and 8 seconds. The total amount of time from wetting of the particles to collection in drum 3%) is preferably less than one minute.

While many other suitable apparatus may be utilized to carry out the process, it is usually preferred that the apparatus provide for quick drying of the wetted particles to prevent unwanted side etfects as previously explained, and to produce a superior product. Where anhydrous sugar or anhydrous whey is used as the wetting agent in the mixture treated by'the apparatus of FIG. 2, the rapid rate of wetting and drying as described above permits a minimal amount, if any, of crystallization during the drying step. The dried aggregated product produced by such apparatus and such process is retained in aggregated form by the relatively strong bonds between the amorphous aggregating agent and the difficult to aggregate particles.

By way of example only, the following are examples of particular instances in which the process was operated:

Example I.-Spray dried egg albumen was dry mixed with anhydrous spray dried lactose in the following ratio: 8 parts of spray dried egg albumen to 2 parts of spray dried anhydrous lactose. After blending was completed, the mixture was aggregated in the conventional manner. After aggregation, the average particle size by weight Was approximately 150 microns.

The moisture content of the nonaggregated powder was 4%, and 5% moisture was added in the aggregator to give a total moisture content to the wetted aggregates of 9%. The wetted aggregates were then quickly redried to 4% moisture with dry air at 350 F.

The aggregated product formed by such process had a density of 0.312 gram per cubic centimeter. This aggregated egg albumen is superior in fiowability, wett-ability and dispersibility to a powdered egg albumen which has been processed in a conventional aggregator without the aid of an aggregating agent.

Example II.Approxirnately 8 parts of spray dried egg yolk was dry blended with approximately 2 parts of spray dried anhydrous lactose. This mixture was then aggre gated in a conventional manner. The moisture content of the nonaggregated powder was 4.0% and 2.6% moisture was added to the mixture to provide an aggregate which before redrying had a moisture content of 6.6% moisture. The wetted aggregates were then quickly redried to 3.5% moisture. The average particle size of the product (by weight) in this case was approximately 240 microns, which was considerably larger than that of the original spray dried yolk. The bulk density was .33 gram per cubic centimeter. The aggregated product which resulted from this process showed markedly improved flowability, wettability and dispersibility over the powdered egg yolk which was processed in a conventional aggregator without the aid of an aggregating agent, and over the original spray dried yolk.

Example [IL-Approximately 8 parts of spray dried whole egg was dry blended with approximately 2 parts of spray dried anhydrous lactose. This mixture was then aggregated in a conventional manner. The moisture content of the nonaggregated powder was 3.4%, and 4.0% moisture was added to the mixture to provide an aggregate which before redrying had a moisture content of 7.4% moisture. The wetted aggregates were then quickly redried to 3.5 moisture. The average particle size of the product (by weight) in this case was approximately 180 microns, which was considerably larger than that of the original spray dried whole egg. The bulk density was .33 gram per cubic centimeter. The product which resulted from this process showed markedly improved flowability, wettability, and dispersibility over the original spray dried whole egg powder.

Example IV.-Approximately 9 parts of wheat flour was dry blended with approximately 1 part of spray dried anhydrous lactose. This mixture was then aggregated in a conventional manner. The moisture content of the nonaggregated powder was 8.2% and 5.8% moisture was added to the mixture to provide an aggregate which before redrying had a moisture content of 14.0% moisture. The wetted aggregates were then quickly redried. The average particle size of the product (by weight) in this case was approximately 100 microns, which was considerably larger than that of the original flour particles. The bulk density was .55 gram per cubic centimeter.

The product which resulted from this process showed markedly improved flowability, wettability, dispersibility over the origin-a1 wheat flour.

It is understood that the present invention is not limited to the particular examples and embodiments of the process and product herein described and illustrated, but embraces all such modified forms thereof as may come within the scope of the following claims.

We claim:

1. In a process for the aggregation of difficult to aggregate finely divided dried particles, the steps of:

(a) mixing a quantity of said difficult to aggregate particles with a quantity of dried particulate amorphous aggregating agent, selected from at least one of the group of materials consisting of anhydrous lactose, anhydrous whey, and modified anhydrous whey, said aggregating agent comprising between about 5% and 50% of the resulting mixture,

(b) subjecting said mixture to controlled wetting while in the presence of a heated high velocity air flow whereby to increase the total moisture content of said mixture by between about 2% and 6%,

(c) said controlled wetting causing said difiicult to aggregate particles to adhere to said aggregating agent to form porous, open structured, divided aggregates, and

(d) quickly drying said aggregates to substantially prevent crystallization of said amorphous aggregating agent.

2. In a process for the aggregation of difiicult to aggregate finely divided dry particles, the steps of:

(a) mixing finely divided amorphous lactose particles with a quantity of said difiicult to aggregate finely divided dry particles, said lactose comprising between about 5% and 50% of the resulting mixture,

(b) subjecting said mixture of dry particles to controlled Wetting in the presence of a heated high velocity air flow whereby to increase the total moisture content of said particles by between about 2% and 6%,

(c) said controlled wetting causing the surfaces of said lactose particles to become moist and sticky whereby to cause said difficult to aggregate particles to adhere to said lactose particles to form porous, open structured, divided aggregates,

(d) quickly subjecting said aggregates to a flow of hot dry air to substantially cause the sticky surfaces of said lactose particles in said aggregates to dry in an amorphous state,

(e) said amorphous lactose bonding said aggregated particles together in relatively firm relation.

3. In a process for the aggregation of finely divided dried egg product particles, the steps of:

(a) mixing a quantity of said dried egg particles selected from at least one of the group of materials consisting of whole egg, egg albumen, egg yolk, and fortified egg products with a quantity of dried particulate amorphous aggregating agent, selected from at least one of the group of materials consisting of anhydrous lactose, anhydrous whey, and modified anhydrous whey, said aggregating agent comprising between about 5% and 50% of the resulting mixture,

- (b) subjecting said mixture of dry particles to controlled wetting in the presence of a heated high velocity air flow whereby to increase the total moisture content of said mixture by between 2% and 6%,

(c) said control-led wetting being sufficient to cause the surfaces of said aggregating agent particles to become moist and sticky whereby to cause said egg product particles to adhere thereto to form porous, open structured divided aggregates,

(d) quickly drying said aggregates to substantially prevent crystallization of said amorphous aggregating agent.

4. In a process for the aggregation of finely divided dry flour particles, the steps of:

(a) mixing a quantity of said dry flour particles with a quantity of dried particulate amorphous aggregating agent, selected from at least one of the group of materials consisting of anhydrous lactose, anhydrous whey, and modified anhydrous Whey, said aggregating agent comprising between about 5% and 50% of the resulting mixture,

(b) subjecting said mixture of dry particles to controlled wetting in the presence of a heated high velocity air flow, whereby to increase the total moisture content of said mixture by between about 2% and 6%,

(c) said controlled wetting being sufficient to cause the surfaces of said aggregating agent particles to become moist and sticky whereby to cause said flour particles to adhere thereto to form porous, open structured divided aggregates,

(d) quickly drying said aggregates to substantially prevent crystallization of said amorphous aggregating agent.

5. In a process for the aggregation of finely divided difficult to aggregate dried cocoa particles, the steps of:

(a) mixing a quantity of said dried cocoa particles with a no greater than equal quantity of finely divided dried particulate amorphous aggregating agent, selected from at least one of the group of materials consisting of anhydrous lactose, anhydrous whey, and modified anhydrous Whey, said aggregating agent comprising between about 5% and 50% of the resulting mixture,

(b) subjecting said mixture of dry particles to controlled wetting in the presence of a heated high velocity air flow, whereby to increase the total moisture content of said mixture by between 2% and 6%,

(c) said controlled Wetting being sufiicient to cause the surfaces of said aggregating agent particles to become moist and sticky whereby to cause said cocoa particles to adhere thereto to form porous, open structured divided aggregates,

(d) quickly drying said aggregates to substantially prevent crystallization of said amorphous aggregating agent.

6. In a process for the aggregation of finely divided difficult to aggregate dried food mix particles, the steps of:

(a) mixing a quantity of said dried food mix particles with a quantity of dried particulate amorphous aggregating agent, selection from at least one of the group of materials consisting of anhydrous lactose, anhydrous Whey, and modified anhydrous whey, said aggregating agent comprising between about 5% and 50% of the resulting mixture,

(b) subjecting said mixture of dry particles to controlled wetting in the presence of a heated high velocity air flow, whereby to increase the total moisture content of said mixture by between about 2% and 6%,

(c) said controlled wetting being sufficient to cause the surfaces of said aggregating agent particles to become moist and sticky whereby to cause said food mix particles to adhere thereto to form porous, open structured divided aggregates,

(d) quickly drying said aggregates to substantially prevent crystallization of said amorphous aggregating agent.

7. A dried egg product comprising:

(a) a quantity of porous, open structured divided aggregates,

(b) the majority of said aggregates consisting of egg product particles selected from at least one of the group of materials consisting of whole egg, egg albumen, egg yolk, and fortified egg products firmly adhered to particles of amorphous aggregating agent selected from at least one of the group of materials consisting of anhydrous lactose, anhydrous whey, and modified anhydrous whey, in random fashion, said amorphous aggregating agent comprising between about 5% and 50% of said product.

8. A flour product comprising:

(a) a quantity of porous, open structured divided aggregates,

(b) the majority of said aggregates consisting of flour particles firmly adhered to particles of amorphous aggregating agent selected from at least one of the group of materials consisting of anhydrous lactose, anhydrous whey, and modified anhydrous whey, in random fashion, said amorphous aggregating agent comprising between about 5% and 50% of said product.

9. A dry cocoa product comprising:

(a) a quantity of porous, open structured divided aggregates,

(b) the majority of said aggregates consisting of difficult to aggregate cocoa particles firmly adhered to particles of amorphous aggregating agent selected from at least one of the group of materials consisting of anhydrous lactose, anhydrous whey, and modified anhydrous Whey, in random fashion, said amorphous aggregating agent comprising between about 5% and 50% of said product.

10. A dry food mix product, comprising:

(a) a quantity of porous, open structured divided aggregates,

(b) the majority of said aggregates consisting of difficult to aggregate food mix particles firmly adhered to particles of amorphous aggregating agent selected from at least one of the group of materials consisting of anhydrous lactose, anhydrous whey, and modified anhydrous Whey, in random fashion, said amorphous aggregating agent comprising between about 5% and 50% of said product.

11. A dried product comprising:

(a) a quantity of porous, open-structured aggregates,

(b) the majority of said aggregates consisting of particles of difiicult to aggregate dry material firmly adhered to particles of amorphous aggregating agent selected from at least one of the group of materials consisting of anhydrous lactose, anhydrous whey, and modified anhydrous whey, in random fashion, said amorphous aggregating agent comprising between about 5% and 50% of said product.

References Cited by the Examiner UNITED STATES PATENTS 2,278,466 4/1942 Musher 991 2,832,686 4/1958 Louder 99-56 2,835,586 5/1958 Peebles 9956 2,851,364 9/1958 Peebles 99-430 2,856,288 10/1958 Peebles 9983 X 2,856,290 lO/1958 Peebles 9983 X 2,893,871 7/1959 Griffin et al. 2,950,204 8/1960 Peebles 9921O 2,977,203 3/1961 Sienkiewicz et al. 233l3 2,995,773 8/1961 Gidlow et a1 181 FOREIGN PATENTS 448,067 6/1936 Great Britain. 527,302 10/ 1940 Great Britain.

OTHER REFERENCES Chemical Engineering, January 1954, pp. 156460. Whittier: Journal of Dairy Science, vol. 27, 1944, pp. 505 to 537; p. 526 relied on.

A. LOUIS MONACELL, Primary Examiner. M. W. GREENSTEIN, Assistant Examiner. 

1. IN A PROCESS FOR THE AGGREGATING OF DIFFICULT TO AGGREGATE FINELY DIVIDED DRIED PARTICLES, THE STEPS OF: (A) MIXING A QUANTITY OF SAID DIFFICULT TO AGGREGATE PARTICLES WITH A QUANTITY OF DRIED PARTICULATE AMORPHOUS AGGREGATING AGENT, SELECTED FROM AT LEAST ONE OF THE GROUP OF MATERIALS CONSISTING OF ANHYDROUS LACTOSE, ANHYDROUS WHEY, AND MODIFIED ANHYDROUS WHEY, SAID AGGREGATING AGENT COMPRISING BETWEEN ABOUT 5% AND 50% OF THE RESULTING MIXTURE, (B) SUBJECTING SAID MIXTURE TO CONTROLLED WETTING WHILE IN THE PRESENCE OF A HEATED VELOCITY AIR FLOW WHEREBY TO INCREASE THE TOTAL MOISTURE CONTENT OF SAID MIXTURE BY BETWEEN ABOUT 2% AND 6%, (C) SAID CONTROLLED WETTING CAUSING SAID DIFFICULT TO AGGREGATE PARTICLES TO ADHERE TO SAID AGGREGATING AGENT TO FORM POROUS, OPEN STRUCTERED, DIVIDED AGGREGATES, AND (D) QUICKLY DRYING SAID AGGREGATED TO SUBSTATIALLY PREVENT CRYSTALLIZATION OF SAID AMORPHOUS AGGREGATING AGENT. 